I think it is too early to tell for the V550 and S500. If you want to be sure before you purchase you will have to wait for some good reviews. If you don't print over 8 X 10 I would be surprised if you could see any difference in your results between the three.

If it isn't too big the V550 looks like a really great camera if you don't need manual controls. The LCD is about twice the resolution of the Z750 and well over twice the resolution of the S500. I like the features and controls.

The S500 doesn't have a viewfinder. That is a deal breaker for someone like me who shoot a lot in the Florida sun. It is tiny and probably competent. I like the past movie mode on the Casios. You can wait for something to happen before you start recording. It records the previous 5 seconds from the buffer and continues recording until you stop it.

I have a Z750 and am very pleased with it. The only thing that keeps me from recommending it wholeheartedly is that many people have developed lens errors from having the lens try to extend in a pocket or case. Most people get it sorted out, but it is something you have to be careful with. Leave in it factory presets and it is a fine point and shoot. Some of the earlier models require you to turn the sharpening, contrast and saturation down one notch, but that is a one time effort. Most cameras let you set it to either return to defaults when you turn it off or keep your settings. The Z750 lets you choose each item individually whether you want it to reset or keep the settings. The control setup is the best I have ever seen on a small camera and better than many large ones.

I doubt you would go wrong with any of them. I don't like not having a viewfinder, but many people muddle through with the LCD even when it is hard to see and they have a viewfinder available. The only way to be sure to not develop a lens error on the Z750 is to put it in audio record mode when you switch it off. It is on the mode dial and it is easy to switch back to snapshot mode, but it is more hassle that there needs to be IMO.

The only way to be sure to not develop a lens error on the Z750 is to put it in audio record mode when you switch it off. It is on the mode dial and it is easy to switch back to snapshot mode, but it is more hassle that there needs to be IMO.